首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   84984篇
  免费   5285篇
  国内免费   498篇
耳鼻咽喉   769篇
儿科学   3102篇
妇产科学   2063篇
基础医学   11410篇
口腔科学   1019篇
临床医学   9945篇
内科学   16628篇
皮肤病学   1523篇
神经病学   7490篇
特种医学   2334篇
外国民族医学   54篇
外科学   8885篇
综合类   1842篇
现状与发展   1篇
一般理论   101篇
预防医学   9861篇
眼科学   1359篇
药学   5243篇
  19篇
中国医学   743篇
肿瘤学   6376篇
  2024年   442篇
  2023年   844篇
  2022年   1417篇
  2021年   2677篇
  2020年   1712篇
  2019年   2394篇
  2018年   2722篇
  2017年   1976篇
  2016年   2037篇
  2015年   2274篇
  2014年   3059篇
  2013年   4283篇
  2012年   6120篇
  2011年   6237篇
  2010年   3497篇
  2009年   2996篇
  2008年   4994篇
  2007年   4997篇
  2006年   4668篇
  2005年   4510篇
  2004年   4047篇
  2003年   3691篇
  2002年   3475篇
  2001年   1414篇
  2000年   1290篇
  1999年   1283篇
  1998年   795篇
  1997年   638篇
  1996年   551篇
  1995年   511篇
  1994年   464篇
  1993年   399篇
  1992年   648篇
  1991年   634篇
  1990年   592篇
  1989年   533篇
  1988年   560篇
  1987年   457篇
  1986年   469篇
  1985年   469篇
  1984年   372篇
  1983年   289篇
  1982年   240篇
  1981年   261篇
  1980年   193篇
  1979年   274篇
  1977年   184篇
  1976年   171篇
  1974年   185篇
  1972年   179篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
21.
22.
23.
It is well established that the circadian clock of the suprachiasmatic nuclei (SCN) is entrained by light. More recently, the potent effects of arousing, non-photic cues on the clock have been recognized. The neural mediators of non-photic entrainment are yet to be identified. To examine the contribution of the thalamic intergeniculate leaflet (IGL) and its NPY-immunopositive projection, the geniculo-hypothalamic tract to non-photic entrainment by arousal, male Syrian hamsters received lesions of the IGL (IGLX) which ablated NPY-immunoreactivity in the SCN. Their circadian responses to both photic and non-photic cues were then tested. Lesions resulted in a delay in the timing of activity onset following lights out, but had no effect on the behavioural or cellular circadian responses to phase-advancing light pulses presented at circadian time (CT) CT19 (where CT12 represents the time of activity onset). Injection with a benzodiazepine (chlordiazepoxide, 100 mg/kg) at CT6 suppressed wheel-running, increased general locomotion of intact controls and induced large phase advances of the circadian rhythm of wheel-running. Chlordiazepoxide also inhibited wheel-running in lesioned animals, but there was no significant increase in general locomotion and the lesioned animals did not phase advance. Serial arousal by injection of saline at intervals of 23.5 h for 6 days entrained the circadian rhythm of wheel-running of intact hamsters and was associated with an increase in general locomotor activity. Entrainment by serial arousal was abolished by IGLX. However, the lesioned animals did show a clear behavioural response to every presentation of the non-photic cue. These results show that the IGL is a necessary component of the neural pathways mediating both arousal- and benzodiazepine-induced non-photic entrainment.  相似文献   
24.
25.
26.
27.
The aim of this study was to investigate the value of elemental diet in steroid-resistant and steroid-dependent Crohn's disease. Elemental diet (Vivonex HN, 39.4 +/- 9.2 kcal/kg/d) was delivered through a nasogastric tube at a constant rate. Twenty therapeutic periods lasting from 20 to 74 days (median, 32 days) were undertaken in 18 patients. Elemental diet was well tolerated. Mean values of hemoglobin, serum albumin, and serum transferrin increased significantly through the therapeutic period; body weight and anthropometric data did not change significantly. The short-term response to elemental diet was excellent in 11 cases, demonstrated by achievement of clinical remission and steroid withdrawal; six patients had an incomplete remission and remained slightly active or had to be maintained under low dose steroids; three patients did not respond to therapy and had to be operated upon. During the follow-up (6-30 months), 8 patients out of 17 had a relapse. Relapse was controlled by medical therapy in 5 cases and led to surgery in the 3 other cases. We conclude that elemental diet, as total parenteral nutrition, is an effective therapy of steroid-resistant and steroid-dependent Crohn's disease. However, elemental diet does not prevent relapse.  相似文献   
28.
Sera from 43 leprosy patients were tested for antibodies that bound to normal human nerve. Thirty-eight percent showed positive staining as demonstrated by indirect immunofluorescence. Only 1 out of 30 control sera tested displayed similar staining. Western blots of myelin and neural intermediate filament (IF) proteins were tested with patient sera. Two of the anti-neural antibody (ANeAb)-positive leprosy sera bound to the P0 protein of PNS myelin. All 17 ANeAb-positive leprosy sera displayed 2 or more bands in the molecular weight range of Mr 45 000-55 000, when tested against IF proteins. One explanation for these findings is that leprosy patients produce antibodies to intermediate filament (IF) proteins released subsequent to the bacterial invasion of the peripheral nerves. The importance of these autoantibodies in the pathogenesis of leprosy is discussed.  相似文献   
29.
B antagonists eye drops are most effective for the treatment of chronic open angle glaucoma. By this way of administration they have a very good systemic bioavailability. Bronchial, and cardiovascular effects of three of these topicals: timolol, carteolol and metipranolol have been evaluated in three parallel groups of asthmatic patients. The three topics induce bronchoconstriction without significant difference between them, and lower heart rate (sometimes very intensely) whatever the B antagonist studied. From these data, it is recommended to practitioners to follow carefully the rules of administration of B blockers, even in eye drops.  相似文献   
30.
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号